Hamster acting differently!

[sgtgus]

Hi! My hamster has recently chosen a different spot of his terrarium to sleep in. I thought it was weird he was choosing under his water bottle instead of in his house so I rearranged all his stuff so his house was in that corner and now he’s sleeping in it.

This is also the third or fourth night in a row he has not run on his wheel or really move around that much. I just checked on him and he was sitting in his house. This is weird for him too as usually he’d be running until 6am.

I am not sure if he’s just having a couple bad days or if something is seriously wrong. I moved back home from university a couple days ago with him so I thought he was just adjusting but now I’m not sure. What can I do? Should I take him to the vet?